Answer:
In the case of an exothermic reaction, the reactants are at a higher energy level as compared to the products, as shown below in the energy diagram. In other words, the products are more stable than the reactants. Overall Δ H ΔH ΔH for the reaction is negative, i.e., energy is released in the form of heat.
Explanation:
Give 264.2g of (NH4)2SO4, calculate the
a) amount of (NH4)2SO4
b) number of ions
c) number of atoms
d) number of H atoms
e) number of N atoms
With workings please! Thanks so much!
Answer:
D.
Explanation:
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Será lançado na próxima quarta-feira, 1º de julho, em São Bernardo do Campo (SP), o primeiro ônibus brasileiro a hidrogênio. [...] O projeto Ônibus Brasileiro à Célula Combustível a Hidrogênio é o ponto de partida para o desenvolvimento de uma solução mais limpa para o transporte público urbano no Brasil. (Disponível em: Acesso em: 19 out. 2009.) Quanto aos processos químicos envolvidos na produção de energia elétrica em células de combustíveis a partir do oxigênio e do hidrogênio, é correto afirmar:
Which element has a smaller ionic radius than magnesium (Mg)?
A) Rb
B) Al
C) Ca
D) Na
Answer:
Na has atomic number 11
which is less than magnesium has atomic number 12
ANSWER IS D
Explanation:
aluminum or Al is atomic 13 and Ca or calcium is atomic number 20 and rubidium or Rb is atomic number 37
Which is TRUE about 'acidified' water acting on rocks?
Please give 1 answer.
A.
Peaty soil water does not cause weathering
B.
Limestone is eroded faster than basalt rock by this type of weathering
c.
It is an example of physical weathering
D.
Nearly neutral water will not weather rocks
EXAMPLES OF PURE SUBSTANCES
Answer: Water, tin, sulfur, sucrose, salt, and etc.
Explanation: The photo has more examples
Helppppp plz ASAP DON’T GUESS
Explanation:
A B C D isme koyi ans hain doond lo
chemical symbol for an atom of lithium
Answer:
Li
Explanation:
It's on the periodic table.
PLEASE HELP!!!
The options are:
A. Nitrogen.
B. Neon.
C. Hydrogen chloride.
D. Sulfur dioxide.
Answer:
Hydrogen Chloride
Explanation:
They will be able to dissolve quicker than the rest
Answer:
C. Hydrogen chloride.
Explanation:
Hydrogen chloride gas will diffuse most quickly.
Hope it is helpful....How does chemistry affect sports?
a shiny brown colured metal onhaeting in air becomes black in colour when hydrogen gas is passed over the black substance it regain its original colour a]what type of chemical reaction takes place in each of the two given steps
Oxidation reaction
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which metals or non-metals are liquid at a room temperature of 25°C?
Answer:
gallium
Explanation:
it is the old melting in a hot cup of coffee spoon
Answer:
Elements That Are Liquid at 25°C
•Bromine
•mercury
Explanation:
The metal which exist as a liquid at room temperature is mercury.
Non-metal which exist as a liquid at room temperature is bromine.
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Calculate the heat energy, in kJ, needed to increase the temperature of 375g of water by 45.0°C.
Explanation:
https://socratic.org/questions/how-much-heat-kj-is-needed-to-raise-the-temperature-of-100-0-grams-of-water-from#216827
How much energy does a 930 nm wave of light have? (The speed of light in a vacuum is 3.00 x 108 m/s, and Planck's constant is 6.626 x 10-34 J·s.)
A. 4.68 x 10^18 J
B. 2.14 x 10^-19 J
C. 1.85 x 10^-31 J
D. 4.21 x 10^35 J
Answer:
B. 2.14 x 10^-19 J
Explanation:
The energy of a wave of light can be obtained using the equation:
E = h*c/λ
Where E is the energy in joules,
λ is wavelength = 930nm = 930x10⁻⁹m
h = Planck's constant = 6.626x10⁻³⁴Js
c = Speed of light = 3.00x10⁸m/s
Replacing:
E = 6.626x10⁻³⁴Js*3.00x10⁸m/s/930x10⁻⁹m
E = 2.14x10⁻¹⁹J
Right option is:
B. 2.14 x 10^-19 J
The expression below was formed by combining different gas laws. V is proportional to StartFraction n T over P EndFraction. Which law was used to determine the relationship between the volume and the number of moles in this equation?
Answer:
The Ideal gas law
Explanation:
From the given question, we have:
V [tex]\alpha[/tex] [tex]\frac{nT}{P}[/tex]
where each variable has its usual meaning.
Thus,
V = [tex]\frac{nRT}{P}[/tex]
where R is the ideal gas constant
cross multiply to have;
PV = nRT
This implies that the volume of the gas is directly proportional to the number of moles of the gas.
Therefore, the law can be used to determine the relationship between the volume and number of moles is the ideal gas law.
Which reaction will most likely take place based on the activity series? Li > K Ba CaNa > Mn > Zn > Cr> Fe> Cd Ni > H > Sb > Cu > Ag > Pd > Hg > Pt a. Ag+FeCl 3 b, Zn + CaO C. Ba+Na 2 CO 3 d . Cr+KNO3
Answer:
Among the given reactions,
a. Ag+FeCl 3
b, Zn + CaO
C. Ba+Na 2 CO 3
d . Cr+KNO3
which reaction is likely to take place based on the reactivity series?
Explanation:
The metal reactivity series is:
Li > K> Ba >Ca>Na > Mn > Zn > Cr> Fe> Cd Ni > H > Sb > Cu > Ag > Pd > Hg > Pt
The highly reactive metal will displace the less reactive metal from its compound during a displacement reaction.
a. Ag+FeCl 3
Ag is less reactive than Fe, so Ag cannot displace Fe from its compound.
This reaction also does not occur.
b, Zn + CaO
Zn is less reactive than Ca, so it cannot displace Ca from its compound.
This reaction does not occur.
C. Ba+Na 2 CO 3
Ba is more reactive than Na, so Ba displaces Na from its compound.
This reaction is possible.
d . Cr+KNO3
Cr is less reactive than K, so it cannot displace K from its compound.
Hence, This reaction is not possible.
Answer:
option c) Ba+Na 2 CO 3 -> BaCO3 +2Na
Answer:
C. Ba+Na 2 CO 3 -> BaCO3 +2NaKHP, the acid used in this experiment,
stands for potassium hydrogen
phosphorous.
True
False
Answer:
false
Explanation:
standard form is Potassium hydrogen phthalate
What does Seltzer Water have in common with Limestone ?
Draw the structure formula of 2methylbutanoate
Answer:
[tex]CH _{3}CH(CH _{3})CH _{2}COO {}^{ - } \\ \\ [/tex]
Find the boiling point of a solution of 2.00 m solution of sodium chloride, NaCl, in water (kb= 0.512°C, bp= 100.0°C)
Answer: Boiling point of the given solution is [tex]102.048^{o}C[/tex].
Explanation:
Given: Molality = 2.00 m
[tex]k_{b} = 0.512^{o}C[/tex]
Now, equation for dissociation of water is as follows.
[tex]H_{2}O \rightarrow H^{+} + OH^{-}[/tex]
As it is giving 2 ions upon dissociation. So, the value of i = 2.
Formula used to calculate change in temperature is as follows.
[tex]\Delta T = i \times k_{b} \times m[/tex]
where,
i = Van't Hoff factor
[tex]k_{b}[/tex] = molal boiling point elevation constant
m = molality
Substitute the values into above formula as follows.
[tex]\Delta T = i \times k_{b} \times m\\= 2 \times 0.512^{o}C \times 2.00 m\\= 2.048^{o}C[/tex]
As the boiling point of water is [tex]100^{o}C[/tex]. Hence, the boiling point of solution will be as follows.
[tex]\Delta T^{'}_{b} = 100^{o}C + 2.048^{o}C\\= 102.048^{o}C[/tex]
Thus, we can conclude that boiling point of the given solution is [tex]102.048^{o}C[/tex].
What properties can be used to identify substance and why?
Answer:
All substances can be characterized by their unique sets of physical and chemical properties. Properties that can be determined without changing the composition of a substance are referred to as physical properties. Characteristics such as melting point, boiling point, density, solubility, color, odor, etc.
Teniendo en cuenta la siguiente reacción quimica: Mn (NO3)2 + NaBiO; + HNO, HMnO₂+ Bi (NO3)3 + NaNO3 + H₂O ¿Cuánto Bi (NO₂), se obtiene a partir de 650 g de Mn (NO₂)2 y 700 g de NaBiO, si la eficiencia del proceso es de un 80%?
Answer:
La masa de Bi (NO₃) ₃ producida es de aproximadamente 2.117,09 gramos
Explanation:
La ecuación química de la reacción se presenta como sigue;
2Mn (NO₃) ₂ + 5NaBiO₃ + 14HNO₃ → 2HMnO₄ + 5Bi (NO₃) ₃ + 5NaNO₃ + 7H₂O
La masa dada de Mn (NO₃) ₂ = 650 g
La masa de NaBiO₃ = 750 g
El número de moles de Mn (NO₃) ₂ = 650 g / (178.95 g / mol) ≈ 3.63 moles
El número de moles de NaBiO₃ = 750 g / (279.968 g / mol) ≈ 2.68 moles
Por lo tanto, el NaBiO₃, es el reactivo limitante, y el rendimiento teórico de Bi (NO₃) ₃ ≈ 5/2 × 2.68 = 6.7 moles
Dado que la eficiencia del proceso es del 80%, el rendimiento real de Bi (NO₃) ₃ = 0,8 × 6,7 moles = 5,36 moles de Bi (NO₃) ₃
La masa molar de Bi (NO₃) ₃ ≈ 394,98 g / mol
La masa de Bi (NO₃) ₃ = 394,98 g / mol × 5,36 moles ≈ 2,117,09 g
La masa de Bi (NO₃) ₃ produjo ≈ 2,117.09 g
Which statements are correct regarding the Law of Conservation of Matter and Energy?
Matter or energy can create itself.
Matter or energy was created by known principles of physics and chemistry.
Matter or energy can change from one form to the other.
The law agrees with the Biblical account of Creation
(more than one answer)
Answer:
Matter or energy can change from one form to the other
Explanation:
The law of conservation of energy states that energy can neither be created nor destroyed but can only be transformed i.e. changed from one form to another. For example, mechanical energy can be changed to electrical energy.
Likewise, the law of conservation of mass/matter states that matter can not be destroyed or created but can change via physical or chemical means to conserve it. For example, matter can change from liquid state to gaseous state.
From the above two laws, it can be said that "matter or energy can change from one form to the other".
The frequency of an X ray is 6.5 x 1018 Hz. What is the X ray’s wavelength? .
Answer:
The X ray’s wavelength is 4.61*10⁻¹¹ m
Explanation:
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).
Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).
The propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave's disturbance propagates along its displacement. Relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:
v = f * λ.
In this case:
The frecuency f= 6.5*10¹⁸ Hz The speed v=c= 3*10⁸ [tex]\frac{m}{s}[/tex]Replacing:
3*10⁸ [tex]\frac{m}{s}[/tex]= 6.5*10¹⁸ Hz* λ
Solving:
[tex]wavelength= \frac{3*10^{8} \frac{m}{s} }{6.5*10^{18} Hz}[/tex]
λ= 4.61*10⁻¹¹ m
The X ray’s wavelength is 4.61*10⁻¹¹ m
Determine if the following two structures are
identical, isomers, or unrelated?
Answer:
its C........................
The following two structures are Isomers.
What are isomers and examples?
Isomers are compounds that contain exactly the same number of atoms, i.e., they have exactly the same empirical formula, but differ from each other by the way in which the atoms are arranged. Examples of isomers with the formula C8H10 are ethyl benzene, m-xylene, p-xylene, and o-xylene.
What are the 3 types of isomers?
There are three types of structural isomers: chain isomers, functional group isomers, and positional isomers.
What are isomers in biology?
Isomers are molecules with the same chemical formula but have different structures. Isomers differ in how their bonds are positioned to surrounding atoms.
Learn more about Isomers in biology at https://brainly.com/question/18474884
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32. Calculate the pH of a solution at 1.00 x 10- MIH") and identify the substance as an acid or base,
Answer:
[tex]{ \boxed{ \tt{formular : pH = - log[H {}^{ + } ]}}} \\ pH = - log(1.00 \times {10}^{-6} ) = 6: it's an acid\\ since \: we \: lack \: the \: exponent, \: this \: question \: is \: unsolvable \\ { \green{ \bf{take \: note}}} :{ \tt{pH \: below \: 7 \: that \: is \: { \red{acidic}}. \: \: pH \: greater \: than \: 7 \: is \: { \red {basic}}}}[/tex]
Which of the following increases the ratio?
Both β+ and β– decay
Only β– decay
Neither β+ nor β– decay
Only β+ decay
Answer:
Only β+ decay
Explanation:
In positron emission, a proton is converted into a neutron and a positron. An anti neutrino is a particle that serves the purpose of balancing the spins.
During positron emission, the mass number to the daughter nucleus is the same as that of the parent nucleus but the atomic number of the daughter nucleus is less than that of the parent nucleus by one unit.
Positron emission increases the neutron/proton ratio.
two reactants to produce sodium carbonate salt?
Answer: equivalent amounts of sodium hydroxide and a solution of sodium hydrogen carbonate
Explanation:
What is the molarity of 4 mol of NaOH dissolved in 2 L of water? O A. 0.5 M OB. 8 M O C. 2M D. 4 M
Answer:
concentration = mol/volume = 4/2 = 2M
What effect does the pH of water have on radish seed germination?
Answer:
High pH negatively affected the germination rate of seeds from most species, but had no effect on the per cent germination of any of the species. The higher concentration of the nutritious solutions affected negatively the germination level and rate
Explanation:
Subtract to find the temperature changes
for the water and the metal.
Answer:
???what metal????????????